During the past year, I've struggled with postpartum depression and recently began taking medication. My depression--which manifested as severe irritability, anxiety and irrational behavior--affected both home and work. My planned three-month maternity leave from my company extended to five, and even after that, I struggled. With treatment, I finally feel like I have my life back and am able to be productive again.

A survey recently released by the National Mental Health Association and the American Medical Women's Association found that depression is the No. 1 obstacle preventing women from being successful in the workplace. In the survey, 83 percent of working women cited depression as a greater barrier to professional success than child and elder care responsibilities, pregnancy and sexual harassment. Women with depression left work early or didn't return from lunch, avoided contact with coworkers and were unable to face work.

This was a survey of employees, but entrepreneurs, too, can feel limited by depression. "There have been times when I feel incapable of working to my full potential," says Beth Shaw, 40, president of Yogafit Training Systems Worldwide in Torrance, California. "I just didn't want to go to work. I lost my creativity, and I was just suffering."

Shaw was diagnosed with depression in her mid-20s and was prescribed various antidepressants, but found natural supplements to be most helpful. She says she can now cope and has built her business from a living room venture to a $4 million company.

To manage her depression, Shaw exercises daily, eats organic and takes supplements. "I stay present in the moment and try to become the witness to my mood and catch it before it gets too dark. I monitor myself constantly. I walk a lot," says Shaw. "Getting rid of stressors is key."

Crystal Cook was depressed when she was 19. She says she shut out others and turned into a "mean workaholic."

"Often, it has seemed through my life that the depression is most likely to resurface when I allow anger or insecurity to keep me from speaking my truth--in business or otherwise," says Cook, the 37-year-old owner of Sol Day Spa in Steamboat Springs, Colorado.

Cook went to therapy for several years and took antidepressants, but has managed her tendency toward depression by maintaining a healthy balance in her life and by helping others. She sits on the board of Mental Health America, a nonprofit organization. "I learned some great skills and a lot about myself in therapy," says Cook. "It helps me every day to be clear about who I am as a person, my unique abilities, my focus, my 'buttons' and, mostly, the warning signs of shutting down."

Forty-year-old Marina Kushner, president of SoyCoffee.com in Brooklyn, New York, was prone to depression since early childhood. Her mother never considered that her daughter might have a mental issue.

Kushner was diagnosed with major depression in 2003 and treated with medication, and she says that her depression actually led her to start her own business. "I couldn't consider looking for a job since interaction with others was difficult," she explains. "I felt inner resistance to talking to anyone. I practically forced myself to talk and sometimes still do, although I feel much better now."

While looking for an explanation for her inability to concentrate, Kushner came across information about how caffeine can trigger central nervous disorders. She wrote a book based on what she learned called The Truth about Caffeine, started the nonprofit organization Caffeine Awareness Alliance and developed a caffeine-free coffee substitute--Soyfee.

Like Shaw and Cook, Kushner turned to an improved lifestyle and diet and began taking supplements to deal with her depression. "Find someone you trust to help you," says Cook. "Accepting that it's something you'll fight doesn't mean 'it' wins."

Aliza Sherman

Aliza Sherman is a web pioneer, e-entrepreneur and author of eight books, including PowerTools for Women in Business. Her work can be found at mediaegg.com.